• Connect the Cisco IP Phone that does not start up to a different network port that is known to be
good.
• Connect the Cisco IP Phone that does not start up directly to the port on the switch, eliminating the
patch panel connection in the office.
• Verify that the phone is receiving power:
• If you are using external power, verify that the electrical outlet is functional.
• If you are using in-line power, use the external power supply instead.
• If you are using the external power supply, switch with a unit that you know to be functional.
• If the phone still does not start up properly, power up the phone with the handset off-hook. When the
phone is powered up in this way, it attempts to launch a backup software image.
• If the phone still does not start up properly, perform a factory reset of the phone.
• After you attempt these solutions, if the phone screen on the Cisco IP Phone does not display any characters
after at least five minutes, contact a Cisco technical support representative for additional assistance.
Phone Displays Error Messages
Problem
Status messages display errors during startup.
Solution
While the phone cycles through the startup process, you can access status messages that might provide you
with information about the cause of a problem. See the “Display Status Messages Window” section for
instructions about accessing status messages and for a list of potential errors, their explanations, and their
solutions.
Phone Cannot Connect Using DNS
Problem
The DNS settings may be incorrect.
Solution
If you use DNS to access the TFTP server or Third-Party Call Control Manager, you must ensure that you
specify a DNS server.
Configuration File Corruption
Problem
If you continue to have problems with a particular phone that other suggestions in this chapter do not resolve,
the configuration file may be corrupted.
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Phone Displays Error Messages
